Disposable amperometric glucose sensor electrode with enzyme-immobilized nitrocellulose strip

Electrochemical properties of screen-printed carbon paste electrodes (CPEs) with a glucose oxidase-immobilized and hexamineruthenium (III) chloride ([ Ru(NH3)(6)](3+)) containing nitrocellulose (NC) strip were examined. The NC strip (2 x 8 mm) placed on the CPEs printed on polyester (PE) film is tigh tly sealed using another PE film on the top with open edges on both sides. Samples containing macromolecules and particles (e.g. proteins and blood ce lls) are applied at one edge of the NC strip and reach the detection area, chromatographically separating small molecules (e.g. glucose, ascorbate, ac etaminophen, and uric acid) of analytical interests. Since sample volumes a nd the amount of catalytic reagents (mediator and glucose oxidase) are prec isely predefined by the dimension and pore size (8 mum) of the NC strip, th e sensor-to-sensor reproducibility and accuracy of analysis are greatly imp roved. The use of [Ru(NH3)(6)](3+) mediator, which exhibits characteristic substantially lowers the applied potential (0.0 V vs Ag/AgCl) for glucose d etermination and eliminates the interference from other oxidizable species, providing improved analytical results. (C) 2001 Elsevier Science B.V. All rights reserved.